Keyboard of pianos.



P. ANELLI.

KEYBOARD or muos.

APPLICATION FILED NOV- 26, I913.

' Patented May 8,1917.

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Witnesses a" "PIETRO ANELLI, OF CREMONA, ITALY.

KEYBOARD 0F PIANOS.

Specification of Letters Patent.

Patented May 8, 1917.

Application filed November 26, 1913. Serial No. 803,181.

To all whom it may concern:

Be it known that I, Prn'rno ANELLI, a subject of the King of Italy, residing at Piazza F ilodrammatici No. 2, Cremona, Italy, have invented certain new and useful Improvements in and Relating to Keyboards of Pianos; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The subject matter of the present invention is a keyboard for pianos in which the support for the keys can be displaced in such a manner that without varying the position of the keys their effective lever arms are varied so that the force necessary for striking can be increased or decreased.

The accompanyings, show the invention carried into effect.

Figure 1 is a plan View of parts of a keyboard constructed according to my invention.

Fig. 2 is a transverse sectional view of Fig. 1.

Fig. 3 is a similar view to Fig. 1 showing a modified form of construction.

According to this invention, each key 1 is provided with a longitudinal slot or groove 2 adapted to receive a rectangular pin 3 carried by the balance rail 4 said rail being movable and adapted to be displaced longitudinally of the keys. The balance rail 4 is traversed by the screws 5, 6, 7 and 8 one end of which press against suitable thrust plates fixed on the beam 9 while the screws are prevented from moving longitudinally in the reverse direction by means of the collars 18 which bear against the blocks 10, 11, 12 and 13. Threads on the screws 5, 6, 7 and 8 engage the internally threaded sleeves 14, 15, 16 and 17 respectively which are secured to the rail 4 and the screw 5 is X- tended at 19 beyond the keyboard where it is provided with a handle by means of which the said screw can be rotated; rotary movement being, simultaneously transmitted to the screws 6, 7 and 8, by means of the gears 21, 22, 23, 24, 25 and 26 and the chains 27, 28 and 29.

In practice when the handle 20 is operated the screws 5, 6, 7, and 8 are rotated, thereby traversing the balance rail either backward or forward according to the direction of rotation of the handle. During this movement the pins 3 slide along the slots or grooves 2 as the keys are retained in position by pins 30 engaging slots 31. By the said moven'ients the position of the fulcrum of the keys is varied as it is located on the rail 4 and the leverage of the keys and thus the striking power is altered; but whatever the leverage may be, the dip of the keys is always the same as it is limited by a stop 33 adapted to engage the extremities 32 of the keys.

The pins 3 sliding in the slots or grooves 2 of the key prevent lateral displacement of the latter when the balance rail 4 is moved and they also govern the key in its regular operation when the piano is played. If desired the slots 2 may be covered with cloth.

It will be obvious that, if necessary, the number of screws moving the balance rail 4 may be increased or decreased and that the method of controlling the screws and also the transmission from one to the other may be varied if desired.

Referring to Fig. 3 which shows modified means for controlling the balance rail 4 a bell crank lever is pivoted at 35 to a stationary beam 34. One arm 36 of the lever extends beyond the keyboard where it is provided with a suitable manipulating handle or knob while the other arm 37 is connected by means of the adjustable link 38 to the arm 39 of a lever pivoted at 40 to the stationary beam 41, the other arm 42 of the lever being connected to a beam 43 that can be displaced longitudinally as indicated by the arrows 44 and 45. The beam 41 is provided with bell crank levers 47 pivotally connected at 46, any desired number of levers being used. One arm of the lever 47 is articulated to the beam 43 while the other arm is connected through the link 48 with the balance rail 4. In use the knob or handle on the arm 36 of the lever is manipulated to rock said lever so as to impart a backward or forward motion to the balance rail 4 through the interposed links and levers as will be obvious from the drawings.

What I desire to claim is 1. A piano keyboard comprising a balance rail to fulcrum a row of keys, means accessible from the exterior of the keyboard for displacing said balance rail longitudinally of and relatively to said keys, and means whereby the keys are retained in the' same position during the displacement of said balance rail.

2. A piano keyboard comprising a balance rail to fulcrum a row of keys, a row of pins mounted in said rail and engaging said row of keys, means accessible from the exterior of the keyboard for displacing said balance rail longitudinally of and relatively to said keys, and means whereby the keys are retained in the same position during the displacement of said balance rail.

3. A piano keyboard comprising a balance rail to fulcrum a row of slotted keys, a row of pins mounted in said rail and engaging the slots in said keys, means accessible from the exterior of the keyboard for displacing said balance rail longitudinally of and relatively to said keys, and means whereby the keys are retained in the same position dur ing the displacement of said balance rail.

4. A piano keyboard comprising a balance rail to fulcrum a row of keys, means comprising a handle for displacing said balance rail longitudinally of and relatively to said keys, and means whereby the keys are retained in the same position during the displacement of said balance rail.

5. A piano keyboard comprising a balance rail to fulcrum a row of keys, means accessible from the exterior of the keyboard for displacing said balance rail longitudinally of and relatively to said keys, a stationary stop and means co-acting with said stop for retaining the keys in the same position during the displacement of said balance rail.

6. A piano keyboard comprising a balance rail to fulcrum a row of keys, means accessible from the exterior of the keyboard for displacing said balance rail longitudinally of and relatively to said keys, a stationary bar in parallel relation to said balance rail and means co-acting with said bar for retaining the keys in the same position during the displacement of said balance rail.

7. A piano keyboard having keys, a movable balance rail serving as a support for the keys, pins carried by said rail, slots in said keys to receive the pins, screws carried by the said rail, gear wheels and chains interconnecting the screws, a beam, thrust plates on said beam for preventing movement of the screws longitudinally in one di rection, blocks preventing movement of the screws longitudinally in the opposite direction, an operating handle for simultaneously rotating the screws to move the balance rail, and means for preventing the keys moving with the rail.

In testimony whereof, I affix my signature, in presence of two witnesses.

PIETRO ANELLI. Witnesses:

ANGELO Civr'raNooL, LYLE Bonn.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, I). G. 

